BOREAS RSS-18 Level 1b AVIRIS At-Sensor Radiance Imagery Summary: These data were collected and processed by the BOReal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science Team 18 (RSS-18) at the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL). Data were acquired for BOREAS with NASA’s Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). This optical sensor measures images that consist of spectra from 400 to 2500 nm at 10 nm sampling. These spectra are acquired as images with 20 meter spatial resolution, 11 km swath width and up to 800 km length. The measurements are spectrally, radiometrically, geometrically calibrated. Spatially, the data are focused on the BOREAS Northern Study Area (NSA) and Southern Study Area (SSA) near Thompson, Manitoba and Candle Lake, Saskatchewan Canada, respectively. AVIRIS data were collected in 1994 during the Thaw campaign at the Northern and Southern Study Area (NSA and SSA), at the SSA in IFC-1, and at the NSA and SSA in both IFC-2 and IFC-3. In 1996, AVIRIS was deployed in the winter and summer campaigns in the SSA only. Table of Contents * 1 Data Set Overview * 2 Investigator(s) * 3 Theory of Measurements * 4 Equipment * 5 Data Acquisition Methods * 6 Observations * 7 Data Description * 8 Data Organization * 9 Data Manipulations * 10 Errors * 11 Notes * 12 Application of the Data Set * 13 Future Modifications and Plans * 14 Software * 15 Data Access * 16 Output Products and Availability * 17 References * 18 Glossary of Terms * 19 List of Acronyms * 20 Document Information 1. Data Set Overview 1.1 Data Set Identification BOREAS RSS-18 Level 1b AVIRIS At-Sensor Radiance Imagery 1.2 Data Set Introduction These data were collected and processed by the BOReal Ecosystem-Atmosphere Study (BOREAS) Remote Sensing Science Team 18 (RSS-18) at the National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL). The AVIRIS Data Facility (ADF) is responsible for processing AVIRIS data to level-b products (at-sensor radiance), data archiving, data distribution, and assisting with judging the instrument performance. AVIRIS data have been used in a wide variety of atmospheric, land, and ocean studies. For BOREAS, AVIRIS data were collected along with other remotely sensed images to spatially characterize the state of various atmospheric, vegetative, and aquatic components for use in integrated modeling studies. 1.3 Objective/Purpose AVIRIS spectral images record the interaction of atmospheric and surface matter with the solar reflected spectrum through processes of absorption and scattering. Analysis of the measured radiance spectra enables determination of atmospheric and surface constituents. Many of the questions posed in BOREAS are related to the distribution and change of constituents of the atmosphere and surface. 1.4 Summary of Parameters The AVIRIS images provide the total spectral radiance [µW/(cm2 sr nm)] recorded at the sensor position. 1.5 Discussion AVIRIS measures the total incident spectral radiance from 400 to 2500 nm through 224 channels at nominally 10 nm spectral sampling and response function. These data are acquired in 11 km by up to 800 km images with nominal 20 by 20 m resolution. Spectral and radiometric calibrations are determined for AVIRIS at the Jet Propulsion Laboratory prior to each period of operations. With an accurate calibration, AVIRIS radiance data may be analyzed quantitatively to retrieve surface reflectance and derived atmospheric and ecological parameters using radiative transfer codes. Accurate calibration will allow comparison of data acquired at the different BOREAS sites. Analysis with time series of AVIRIS data at the BOREAS sites will also require an accurate calibration of the sensor data. Finally analysis of AVIRIS data in conjunction with other measurements or physical models require calibrated data. . 1.6 Related Data Sets BOREAS RSS-18 Sunphotometer Data BOREAS RSS-18 Ground Reflectance Data BOREAS level-0 ER-2 Navigation Data BOREAS Level-1b MAS Imagery: At-sensor Radiance in BSQ Format BOREAS Level-1b ASAS Imagery: At-sensor Radiance in BSQ Format 2. Investigator(s) 2.1 Investigator(s) Name and Title Dr. Robert O. Green, AVIRIS Experiment Scientist 2.2 Title of Investigation Surface and Atmosphere Measurements and Radiative Transfer Modeling for the Calibration and Validation of the Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) for Quantitative Data Analysis at BOREAS 2.3 Contact Information Contact 1 ---------------- Robert O. Green NASA Jet Propulsion Laboratory Pasadena, CA Phone: (818) 354-9136 Fax: (818) 393-4773 rog@gomez.jpl.nasa.gov Contact 2 ------------------ Jeffrey A. Newcomer NASA Goddard Space Flight Center Greenbelt, MD Phone: (301) 286-7858 Fax: (301) 286-0239 Jeffrey.Newcomer@gsfc.nasa.gov 3. Theory of Measurements An imaging spectrometer measures a continuous spectrum of light for each spatial element of an image. From these spectra, the constituents of the Earth's surface and atmosphere are identified and measured quantitatively based on the fundamental molecular absorption features and particle scattering characteristics. Spectra measured in the range of 400 to 2500 nm contain important molecular absorptions for many constituents of the Earth's surface and atmosphere. Scientific investigations are ongoing using imaging spectrometry data in the disciplines of Ecology, Oceanography, Coastal and Inland Waters, Geology and Soils, Snow Hydrology, the Atmosphere, etc. 4. Equipment: 4.1 Sensor/Instrument Description 4.1.1 Collection Environment The BOREAS AVIRIS spectral images were acquired largely under clear sky conditions. 4.1.2 Source/Platform AVIRIS is installed in the Q-bay of the NASA ER-2 aircraft which flies nominally at approximately 20 km altitude. 4.1.3 Source/Platform Mission Objectives The BOREAS Experiment Plans (1994 and 1996) give information about the overall ER-2 flight patterns. The AVIRIS mission objectives for BOREAS were to acquire high spatial and hyper-spectral resolution digital imagery over selected BOREAS areas during optimally clear days of the BOREAS field efforts in 1994 and 1996. 4.1.4 Key Variables The AVIRIS images provide the total spectral radiance [µW/(cm2 sr nm)] at the sensor. 4.1.5 Principles of Operation Light enters AVIRIS from a 10 by 20 cm scan mirror driven by a 70 percent efficient whiskbroom scan drive at a rate of 12 scans per second. Significant engineering effort was required to develop a scan drive to sweep linearly across the 30 degree (10.4 km at nominal altitude of 19,800 m) field-of-view and then return at nearly twice the speed to start the next imaging scan. The instantaneous field-of-view (IFOV) of AVIRIS is 1 milliradian (19.8 m at altitude of 19,800 m) and translates to 614 crosstrack spatial elements per scan. In the foreoptics, the energy reflected from the scan mirror is magnified and focused on four 200 micron diameter optical fibers. The fibers transmit the light from the foreoptics to one each of four spectrometers. Silica glass fibers with numerical apertures of 0.55 are used to cover the spectral range from 400 to 1200 nanometers. Zirconium fluoride glass fibers with a beryllium fluoride cladding with a 0.55 numerical aperture are used from 1200 to 2500 nm. These high numerical aperture zirconium fluoride fibers were specifically developed for AVIRIS and were the first of their kind. The Zirconium fluoride fibers were found to be less robust than silica. However, initial difficulties were overcome, and the use of fibers was essential to allow independent alignment of the foreoptics and spectrometers as well as meet the compact sensor packaging requirements. AVIRIS uses four off-axis Schmidt spectrometers (A, B, C and D) to measure the light across the wavelength range at maximum grating efficiencies. Light enters the spectrometers from the optical fibers and a spherical mirror collimates and directs it to a diffraction grating where the light is dispersed into its spectral components. The grating is designed with a second order aspheric correction surface. The dispersed light is refocused by the spherical mirror onto the detector focal plane. For the range 400 to 700 nm a linear silicon detector array of 32 elements is used in spectrometer A. Spectrometers B, C and D use 64 element arrays of indium antimonide. Each spectrometer and detector array is optimized for the appropriate spectral range. The signal measured by each detector in the array is multiplexed in the focal plane and then amplified. The amplified signal is then digitized at 12 bits. The digital signal is buffered then merged with engineering, navigation and dark signal data. Navigation data include the X, Y and Z position of the platform from a GPS as well as the roll, pitch and yaw at one second intervals. This data stream is then recorded on a 10.4 gigabyte digital high density tape at a rate of 20.4 megabits per second. An on-board calibrator is an additional component of the AVIRIS sensor. This subsystem contains a stabilized quartz halogen lamp that provides light to the foreoptics end of the optical fibers. AVIRIS data are collected from the on- board calibrator before and after each flight line. A silicon detector feedback circuit as been specifically developed to maintain the stability of the light from the on-board calibrator. In addition, light from the on-board calibrator is sent sequentially through eight different filters providing both radiometric and spectral calibration sources. The AVIRIS sensor and on-board calibrator system are calibrated in the laboratory preceding and following each flight season. During laboratory calibration the spectral, radiometric and geometric characteristics of AVIRIS are determined with respect to laboratory standards. In the six month period each year when AVIRIS is not collecting airborne data, the sensor is maintained and improved at JPL. Since its first flight in 1986, almost every subsystem of AVIRIS has been upgraded. Through these continuous improvements, AVIRIS has continued to incorporate new technology and remain a unique state-of-the-art imaging spectrometer. 4.1.6 Sensor/Instrument Measurement Geometry AVIRIS Instrument/Platform Specifications Platform: NASA/AMES ER-2 Altitude: 19,800 meters (nominal) Ground Speed: 440 knots (814.88 kilometers/hr) Pixel Spatial Resolution: 19.8 meters (at 19,800 meters altitude) Pixels per Scan Line: 614 Scan Rate: 12 scans/second Swath width: 10.4 km at 19,800 m altitude Total Field of View: 30 (plus or minus 15) degrees Instantaneous Field of View: 1.0 milliradian Bits per Channel: 10 through 1994; 12 since 1995 Data Rate: 17 Megabytes/second through 1994; 20.4 since 1995 Visible Calibration: Direct view of Standard Lamp Infrared Calibration: Direct view of Standard Lamp Other Calibration Standards Inflight validation, Quantum Efficient Detector, Cavity Black body. 4.1.7 Manufacturer of Sensor/Instrument AVIRIS was proposed, developed and is maintained at the NASA Jet Propulsion Laboratory 4.2 Calibration 4.2.1 Specifications 4.2.1.1 Tolerance Several calibration standards are used both in the laboratory and in the field to support calibration of AVIRIS. Spectral calibration of AVIRIS is derived from krypton and mercury low pressure emission lamps. Known emission line features from these lamps are used to spectrally calibrate a monochrometer. The monochrometer is used as a calibrated source to establish for each instrument the channel spectral positions and channel spectral response functions. Radiometric calibration, stability, linearity and noise equivalent radiance is derived from the NIST standard lamp maintained within the AVIRIS calibration laboratory. Two Spectralon panels calibrated at the 0.5 percent reflectance accuracy are used as the reflectance standards. 4.2.2 Frequency of Calibration AVIRIS is calibrated at the beginning and end of the flight season in the laboratory. In-flight calibration of AVIRIS occurs at the beginning, middle and end of the flight season. The on-board calibrator is observed by AVIRIS at the beginning and end of each flight line and is used to trace the calibration in detail through the flight season. 4.2.3 Other Calibration Information AVIRIS spectral, radiometric and geometric calibration are provided with each flight line. 5. Data Acquisition Methods As part of the BOREAS aircraft data collection effort, the ADF personnel provided the AVIRIS data to BORIS for use in science investigations. The AVIRIS was flown on NASA's ER-2 aircraft during BOREAS. Maintenance and operation of the instrument are the responsibility of NASA JPL. 6. Observations AVIRIS operated nominally for BOREAS 6.1 Data Notes The following sections were extracted from the errata files (full errata files exist as part of the dataset) on the 1994 and 1996 Format A AVIRIS data tapes. 1994 Errata File ---------------- 1) Operations Period: from 930517 a) Single channel and spatial element noise spikes continue through this period in all spectrometers. Rate: 1 in 300,000 samples. In calibrated data, the spikes are replaced with values computed from spatial neighbors. b) All values in the vignetting file are 1.0. In 1993 and later the vignetting effect is less than 2% and below our ability to accurately measure. 2) Operations Period: from 940301 a) A tendency for the least significant 1 or 2 bits to be flipped in the data was observed. The noise was detected because it occurs in the minor frame sync words, which should have uniform values. The magnitude of the noise (typically 1, 2, or 4) is not large enough to be observed in most channels' data, so it is not known how frequently a data value is affected. In channels with low enough signal to notice these spikes, an average of perhaps 10 in a scene were observed. In calibrated data these noise values may be replaced by the same spike replacement algorithm used on the spikes described in 1) a), but usually their magnitude is not big enough to trip that detection mechanism. Normally in calibrating the data, lines with minor sync errors are dropped. For this period however they are not because this would have resulted in throwing away a lot of good data. Because minor sync errors are ignored in this data, there will occasionally be a line in which the science data is corrupted or missing. 1996 Errata File ---------------- OPERATIONS FROM 951026 TO 961010 a) The detector slew rate artifact that first appeared in the 1995 flight season has been reduced. It may be seen in ratios of bands in and out of strong atmospheric absorptions. b) Occasional downward spikes occur in the spectra about every 15000 spectra. These are replaced when detected in the calibration process. Radiometrically calibrated data undergo spike replacement. Please note that, since this is the only (known) type of spikes in the 1996 data and since the spike filtering algorithm used to detect these spikes differs substantially compared to previous years, the old spike filtering algorithms and the spike thresholds file are no longer used. The spike thresholds file is nevertheless included on the PG tapes for 1996 (for consistency reasons), but all threshold values are set to zero and should not be used. c) Spectral calibration shifts of up to 1.0 nm may occur in 1996 data. This is comparable to previous years and will be corrected in 1997. Radiometric calibration is the best ever at better than 96.5 percent. d) All values in the vignetting file are 1.0. Vignetting effect is less than 2% and below our ability to accurately measure. e) When uncalibrated data is requested, no On-board Calibrator (OBC) correction is applied to the data set. As a result, no OBC correction coefficients are calculated. The OBC correction coefficients file (OCC) written to the PG tape is filled with ones and is not applicable to the uncalibrated data set. OPERATIONS FROM 940404 TO 941130 a) Single channel and spatial element noise spikes occur through this period in all spectrometers. Rate: 1 in 300,000 samples. In calibrated data, the spikes are replaced with values computed from spatial neighbors. b) All values in the vignetting file are 1.0. Vignetting effect is less than 2% and below our ability to accurately measure. c) A tendency for the least significant 1 or 2 bits to be flipped in the data was observed. d) Normally in calibrating the data, lines with minor sync errors are dropped. For this period however they are not. Because minor sync errors are ignored in this data, there will occasionally be a line in which the science data is corrupted or missing. 6.2 Field Notes None. 7. Data Description 7.1 Spatial Characteristics 7.1.1 Spatial Coverage The cross track coverage of an AVIRIS image is nominally 11 km. The length of the images is determined from the start and stop latitude and longitude flown. For BOREAS, the images were collected over the SSA and NSA with some data also collected over the transect between the NSA and SSA. The NAD83 corner coordinates of the SSA are: Latitude Longitude -------- --------- Northwest 54.321 N 106.228 W Northeast 54.225 N 104.237 W Southwest 53.515 N 106.321 W Southeast 53.420 N 104.368 W The NAD83 corner coordinates of the NSA are: Latitude Longitude -------- --------- Northwest 56.249 N 98.825 W Northeast 56.083 N 97.234 W Southwest 55.542 N 99.045 W Southeast 55.379 N 97.489 W 7.1.2 Spatial Coverage Map Each record or flight line name in the following table represents one to several AVIRIS scenes. See the BOREAS Experiment Plan for graphics depicting the general location of flight lines. For specific information about flux tower site coverage, see section 7.2.2. Flight line Start End Start End Start End #Lines Name Latitude Latitude West Long West Long GMT GMT 10-Apr-94 1954 SSA-cal-W 53:07:08 53:20:58 105:41:58 105:41:58 18:01:54 18:03:56 5769 SSA-West-B 53:28:53 54:17:39 106:15:54 106:15:54 18:10:41 18:18:00 3334 SSA-West-Thaw 54:02:30 53:35:28 106:05:22 106:13:56 18:22:12 18:26:08 5761 SSA-West-C 53:28:53 54:17:59 106:07:00 106:06:41 18:32:13 18:39:32 3258 SSA-East-Thaw 53:59:32 53:52:56 105:19:33 104:36:02 18:46:23 18:50:13 4245 SSA-East-J 54:12:23 53:36:08 104:40:59 104:40:59 18:59:14 19:04:27 4447 SSA-East-H 53:35:28 54:12:03 104:58:07 104:58:07 19:10:08 19:15:37 4266 SSA-East-F 54:12:23 53:36:08 105:15:16 105:15:36 19:20:52 19:26:07 4381 SSA-East-K 53:35:28 54:12:03 104:32:25 104:32:25 19:33:18 19:38:42 4290 SSA-EAST-I 54:12:23 53:36:08 104:49:33 104:49:33 19:44:09 19:49:24 4382 SSA-EAST-G 53:35:28 54:12:03 105:06:42 105:06:42 19:54:32 19:59:55 4331 SSA-East-E 54:12:23 53:36:08 105:24:10 105:24:10 20:07:39 20:12:57 5679 SSA-West-D 53:29:12 54:17:39 105:57:47 105:57:47 20:21:33 20:28:44 20-Apr-94 8294 Transect-T 54:59:31 55:54:33 101:40:42 100:15:00 17:52:33 18:03:21 8960 Tansect-U 55:54:53 55:54:33 100:15:20 97:49:59 18:11:00 18:22:45 2342 NSA-Q 56:03:08 55:44:40 98:07:27 98:07:27 18:30:42 18:33:16 2550 NSA-O 55:44:01 56:02:48 98:25:15 98:25:35 18:38:28 18:41:19 2315 NSA-M 56:02:48 55:44:40 98:44:02 98:44:22 18:46:45 18:49:16 2556 NSA-L 55:44:01 56:02:48 98:52:56 98:52:56 18:55:21 18:58:14 2360 NSA-N 56:03:08 55:45:00 98:35:08 98:35:08 19:03:27 19:06:01 2537 NSA-P 55:44:01 56:02:48 98:16:21 98:16:21 19:11:32 19:14:22 2415 NSA-R 56:03:27 55:44:40 97:58:14 97:58:14 19:19:36 19:22:17 3514 NSA-thaw-X 55:53:14 55:53:14 98:04:10 98:55:15 19:29:14 19:33:26 13829 Transect S 39:22:30 54:07:07 101:39:03 104:59:07 19:49:30 20:07:59 28-Apr-94 3567 NSA-Thaw 55:53:14 55:53:14 98:56:34 98:05:29 17:00:20 17:04:35 1597 NSA-Q 55:57:51 55:46:59 98:07:08 98:07:27 17:12:22 17:13:53 1923 NSA-O 55:46:59 56:00:10 98:25:35 98:25:35 17:19:24 17:21:22 1777 NSA-M 56:00:10 55:47:38 98:44:02 98:44:02 17:26:32 17:28:17 1869 NSA-L 55:47:18 56:00:10 98:52:56 98:53:16 17:33:43 17:35:36 1861 NSA-N 56:00:29 55:47:18 98:34:49 98:34:49 17:40:49 17:42:44 1876 NSA-P 55:46:59 56:00:10 98:16:41 98:16:21 17:48:05 17:50:00 1789 NSA-R 56:00:10 55:47:38 97:58:14 97:58:14 17:55:35 17:57:22 1936 NSA -Q 55:46:59 56:00:10 98:07:08 98:07:08 18:03:11 18:05:11 9125 Transect-U 55:54:53 55:54:53 97:49:20 100:15:20 18:12:55 18:24:54 8112 Transect-T 55:54:53 54:59:51 100:15:00 101:40:02 18:31:58 18:42:32 5764 Transect-S 54:59:51 54:40:04 101:38:43 102:58:29 18:49:44 18:57:03 8-Jun-94 4241 NSA-Thaw-X 55:53:14 55:53:14 99:05:08 98:03:30 15:59:04 16:04:16 2842 NSA-R 55:45:20 56:06:25 97:57:54 97:57:34 16:12:17 16:15:33 1872 NSA-P 56:00:49 55:47:18 98:16:21 98:16:41 16:20:05 16:22:01 2101 NSA-N 55:45:20 56:00:10 98:34:49 98:34:49 16:27:19 16:29:33 1867 NSA-L 56:01:09 55:47:38 98:53:16 98:53:16 16:35:11 16:37:06 2076 NSA-M 55:45:39 56:00:29 98:44:02 98:44:02 16:43:49 16:46:01 1890 NSA-O 56:01:09 55:47:38 98:25:55 98:25:55 16:51:20 16:53:15 10479 Boreas 55:54:53 55:54:53 97:48:20 100:41:22 17:09:40 17:23:31 7267 Boreas 55:47:58 54:58:51 100:26:13 101:41:41 17:30:40 17:40:05 21-Jul-94 1995 SSA-Cal-W 53:06:28 53:20:58 105:41:58 105:41:58 16:29:31 16:31:35 3757 SSA-Thaw-Y 53:51:37 53:59:12 104:28:08 105:18:34 16:54:23 16:58:55 4485 SSA-East-G 54:10:05 53:31:31 105:06:42 105:06:42 17:05:55 17:11:27 4138 SSA-Easy-I 53:36:08 54:10:05 104:49:33 104:49:33 17:15:42 17:20:46 3741 SSA-East-K 54:10:44 53:39:06 104:32:25 104:32:25 17:25:59 17:30:28 4040 SSA-East-J 53:37:07 54:10:05 104:40:59 104:40:59 17:35:55 17:40:49 3630 SSA-East-H 54:08:46 53:38:46 104:58:07 104:58:07 17:46:43 17:51:05 4171 SSA-East-F 53:36:08 54:09:45 105:15:16 105:15:16 17:56:24 18:01:29 3514 SSA-Thaw-Z 54:04:09 53:35:08 106:05:02 106:13:56 18:08:07 18:12:19 5207 SSA-West-B 54:18:39 53:32:30 106:15:54 106:15:54 18:29:08 18:35:39 5495 SSA-West-D 53:30:32 54:17:20 105:57:47 105:56:47 18:40:59 18:47:56 5511 SSA-West-C 54:20:18 53:50:58 106:07:00 106:07:00 18:56:46 19:01:01 4-Aug-94 3905 NSA-Thaw-X 47:58:18 55:53:14 120:39:26 98:04:49 19:52:41 15:29:31 2139 NSA - R 55:45:00 55:59:50 97:57:54 97:57:54 15:39:41 15:41:56 1978 NSA - P 56:02:08 55:47:18 98:16:21 98:16:21 15:47:38 15:49:41 2065 NSA - N 55:45:39 56:00:10 98:34:49 98:34:49 15:54:57 15:57:07 1875 NSA - L 56:00:49 55:47:18 98:53:16 98:53:16 16:02:27 16:04:22 1904 NSA - M 55:46:59 56:00:10 98:44:02 98:44:02 16:09:48 16:11:46 1835 NSA - O 56:00:49 55:47:58 98:25:55 98:25:35 16:16:53 16:18:45 9352 Transect U 55:54:53 55:54:53 97:44:03 100:15:40 16:33:56 16:46:13 8296 Transect T 55:57:12 55:12:02 100:11:23 101:21:35 16:53:50 17:02:21 8-Aug-94 3889 NSA-Thaw-X 55:53:14 55:53:14 99:02:10 98:03:50 15:23:36 15:28:19 2262 NSA_R 55:43:41 56:00:29 97:57:54 97:58:14 15:36:19 15:38:47 2180 NSA-P 56:03:27 55:47:18 98:16:01 98:16:21 15:44:12 15:46:32 2292 NSA-N 55:44:01 56:00:29 98:34:49 98:34:49 15:52:30 15:55:00 2175 NSA-L 56:03:08 55:46:39 98:53:36 98:53:16 16:01:24 16:03:43 2120 NSA-M 55:45:00 56:00:29 98:44:02 98:44:02 16:11:52 16:14:06 1973 NSA-O 56:00:29 55:45:59 98:25:55 98:25:35 16:20:25 16:22:28 2105 NSA-Q 55:44:40 56:00:10 98:07:27 98:07:08 16:28:38 16:30:51 8967 Transect U 55:54:53 55:55:13 97:49:20 99:34:48 16:39:20 16:47:51 8290 Transect-T 55:55:53 54:59:51 100:13:41 101:40:22 16:58:55 17:09:45 16-Sep-94 1760 SSA-Cal-W 53:08:46 53:20:58 105:41:38 105:41:58 16:39:15 16:41:00 3953 SSA-East-K 53:38:26 54:11:04 104:37:41 104:32:05 16:47:20 16:52:07 4061 SSA-East-I 54:11:04 53:38:46 104:49:33 104:49:33 17:02:21 17:07:18 3883 SSA-East-G 53:37:47 54:10:05 105:06:42 105:06:42 17:14:50 17:19:33 3726 SSA-East-F 54:08:46 53:38:26 105:15:36 105:15:36 17:28:38 17:33:07 3875 SSA-East-H 53:38:26 54:10:24 104:57:48 104:58:07 17:41:13 17:45:53 4003 SSA-East-J 54:11:24 53:38:26 104:40:59 104:40:59 17:53:26 17:58:17 3391 SSA-E-Thaw-Y 53:52:56 53:59:32 104:36:22 105:18:53 18:05:49 18:09:50 5165 SSA-West-D 54:16:20 53:32:30 105:58:07 105:58:07 18:18:54 18:25:24 5088 SSA-West-B 53:33:10 54:16:20 106:15:54 106:15:35 18:32:45 18:39:07 5077 SSA-West-C 54:16:01 53:32:50 106:07:00 106:07:00 18:48:21 18:54:43 17-Sep-94 8423 BOREAS-Tran-T 54:58:32 55:54:53 101:41:41 100:15:00 15:54:16 16:05:16 1615 NSA - L 55:58:31 55:47:38 98:53:16 98:53:16 16:14:26 16:16:01 2237 NSA - N 55:44:01 55:59:50 98:34:29 98:34:49 16:21:09 16:23:34 1877 NSA - P 56:01:09 55:47:58 98:16:21 98:16:41 16:28:41 16:30:34 2091 NSA - R 55:45:20 55:59:50 97:57:34 97:57:54 16:35:41 16:37:53 2105 NSA - M 56:03:08 55:47:38 98:44:02 98:44:22 16:54:24 16:56:38 2061 NSA - O 55:45:20 55:59:50 98:25:35 98:25:35 17:01:45 17:03:54 2098 NSA - Q 56:03:08 55:47:38 98:07:27 98:07:27 17:09:12 17:11:26 9914 NSA-Thaw-X/Trn 55:53:14 55:53:14 97:45:03 100:15:20 17:21:11 17:34:14 30000 Transect S 55:00:30 53:45:02 101:37:24 106:15:15 17:45:37 18:13:14 7-Mar-96 6376 Prince Albert 53:26:01 54:17:48 106:15:56 106:17:56 19:09:40 19:17:43 5463 Prince Albert 54:19:45 53:30:25 105:57:47 105:57:46 19:23:04 19:29:52 6478 Prince Albert 53:25:35 54:17:40 106:06:33 106:06:37 19:36:25 19:44:36 4260 Prince Albert 54:14:24 53:36:21 105:06:42 105:06:37 19:51:44 19:56:52 5143 Prince Albert 53:31:35 54:12:01 104:57:38 104:57:55 20:03:49 20:10:10 4703 Prince Albert 54:11:17 53:29:00 104:49:16 104:49:28 20:16:37 20:22:23 5225 Prince Albert 53:31:18 54:12:06 104:32:16 104:32:10 20:25:51 20:32:18 5148 Prince Albert 54:16:06 53:28:57 104:40:55 104:40:54 20:38:14 20:44:34 8-Aug-96 5945 P.A. West 53:27:05 54:17:46 106:24:35 106:24:36 16:24:39 16:32:07 5565 P.A. West 54:19:00 53:30:27 106:06:54 106:06:49 16:37:17 16:44:14 5830 P.A. West 53:28:48 54:18:10 106:15:38 106:15:36 16:49:24 16:56:43 5593 P.A. West 54:18:42 53:30:24 105:57:46 105:57:49 17:01:45 17:08:43 4566 P.A. East 54:14:56 53:36:29 105:23:50 105:23:54 17:22:26 17:28:00 4428 P.A. East 53:34:55 54:12:02 105:06:35 105:06:29 17:33:57 17:39:18 4486 P.A. East 54:13:46 53:44:23 105:15:07 105:15:18 17:43:05 17:47:21 4535 P.A. East 53:33:58 54:03:20 104:57:56 104:57:53 17:53:18 17:57:33 4476 P.A. East 54:14:01 53:36:24 104:40:53 104:40:54 18:03:32 18:08:59 4512 P.A. East 53:34:30 54:03:48 104:49:09 104:49:12 18:14:28 18:18:43 7.1.3 Spatial Resolution At the nominal ER-2 operating altitude of 19,800 m, the AVIRIS provides across- track pixel resolutions of 19.5 m at nadir to 21.4 m at the scanning extremes. The along-track resolution is dependent on the forward velocity of the aircraft and the scan rate which is usually 12 scans per second. 7.1.4 Projection The images covering the BOREAS areas are stored in their raw spatial form with pixel size increasing from nadir to the scanning extremes of 15 degrees. There is navigation and position data delivered with AVIRIS that allow ephemeris based projection of the spectral images. 7.1.5 Grid Description Not applicable. 7.2 Temporal Characteristics 7.2.1 Temporal Coverage AVIRIS data were acquired on the following dates: 19-Apr-94 20-Apr-94 28-Apr-94 08-Jun-94 21-Jul-94 04-Aug-94 16-Sep-94 17-Sep-94 07-Mar-96 14-Aug-96 7.2.2 Temporal Coverage Map flight run scene site_name BOREAS sites 940419 2 1,2,3 SSA-Cal-W 940419 3 2 SSA-West-B OASP 940419 4 6 SSA-West-Thaw OASP 940419 6 2 SSA-East-Thaw OBS 940419 6 5 SSA-East-Thaw OJP 940419 6 6 SSA-East-Thaw YJP 940419 7 4 SSA-East-J OJP 940419 7 5,6 SSA-East-J YJP,FEN (FEN tower in 5, WAB extends into 6) 940419 12 5 SSA-East-G OBS (site near edge, may also want scene 6) 940420 6 2 NSA-O OBS 940420 6 3 NSA-O FEN 940420 9 ? NSA-N QUICKLOOK NOT AVAILABLE 940420 10 ? NSA-P QUICKLOOK NOT AVAILABLE 940420 12 2 NSA-THAW YJP 940420 12 3 NSA-THAW FEN,OBS 940420 12 4 NSA-THAW OJP 940428 2 3 NSA-THAW OJP 940428 2 4 NSA-THAW FEN,OBS 940428 4 2 NSA-O FEN,OBS 940428 7 1,2 NSA-N OJP (tower in 2, WAB may extend into 2) 940428 8 2 NSA-P YJP 940608 2 4 NSA-THAW OJP 940608 2 5 NSA-THAW FEN,OBS 940608 2 6 NSA-THAW YJP 940608 4 2 NSA-P YJP 940608 5 3 NSA-N OJP 940608 8 2 NSA-O FEN,OBS 940721 2 1,2,3 SSA-Cal-W 940721 3 ? SSA-THAW-EAST (quicklook for scenes 7 and 8 found,no sites, did not find quicklook for scenes 1-6) 940721 4 3 SSA-EAST-G OBS 940721 7 3 SSA-EAST-J FEN 940721 7 4 SSA-EAST-J YJP,OJP 940721 10 6 SSA-WEST-THAW OASP 940721 11 9 SSA-WEST-B OASP 940804 2 3 NSA-THAW OJP 940804 2 4 NSA-THAW OBS 940804 2 5 NSA-THAW FEN 940804 2 6 NSA-THAW YJP 940804 4 2 NSA-P YJP 940804 5 3 NSA-N OJP 940804 8 2 NSA-O OBS 940808 1 3 NSA-THAW OJP 940808 1 4 NSA-THAW OBS 940808 1 5 NSA-THAW FEN 940808 1 6 NSA-THAW YJP (cloud shadow over tower) 940808 3 2,3 NSA-P YJP (near edge of scene 2, clouds all over, tower apparently clear) 940808 4 3 NSA-N OJP 940808 7 2 NSA-O FEN,OBS (large cloud next to OBS) 940916 2 1,2,3 SSA-Cal-W 940916 5 5 SSA-EAST-G OBS 940916 8 4 SSA-EAST-J OJP,YJP 940916 9 1 SSA-THAW-EAST OJP,YJP 940916 9 5 SSA-THAW-EAST OBS 940916 11 1 SSA-WEST-B OA 940917 5 3 NSA-N OJP 940917 9 2 NSA-O FEN, OBS 940917 10 7 NSA-P OJP 940917 11 4,5,6,7 NSA-Thaw-X YJP,FEN,OBS,OJP (respectively) Additional AVIRIS imagery is available over the SSA on 07-Mar and 14-Aug-1996 however. 7.2.3 Temporal Resolution See section 7.1.2 7.3 Data Characteristics Data characteristics are defined in the companion data definition file (aviris1b.def). 7.4 Sample Data Record Sample data format shown in the companion data definition file (aviris1b.def). 8. Data Organization 8.1 Data Granularity The smallest obtainable unit of data for Level-1B AVIRIS images is a single flight line. Each flight line is broken up into one to several scenes. A scene represents AVIRIS image data collected over a portion of a site during one flight line 8.2 Data Format(s) The image inventory data file contains numerical and character fields of varying length separated by commas. The character fields are enclosed with a single apostrophe marks. There are no spaces between the fields. Sample data records are shown in the companion data definition file (aviris1b.def). There are two AVIRIS data formats currently in the BORIS archive. The AVIRIS data format was changed in July 1997. The old format is referred to as PG, the new format is referred to as Calibrated AVIRIS Spectral Image. All data at the ADF back to 1992 are being reprocessed to the newer format. Most of the BOREAS data is in the PG format, only the summer 1996 data arrived in the newer format. Old (PG) Format --------------- A full description of the AVIRIS data will not be given here since the format is rather involved, it is given in the Description File on each tape, and software is available to read the tapes. Instead an overall product description follows. All the BOREAS level-1b AVIRIS data are in what the AVIRIS Data Facility calls ‘VAX format with fixed length file headers’. The VAX format refers to the byte ordering of certain (but not all) binary multi-byte fields. The fixed length file headers are included at the start of a majority of the files and are described in detail in the Description File and software. The tape records contain a variable number of bytes with the largest records containing 32,768 bytes. A given tape of level-1b AVIRIS images contains one set of Introductory files followed by up to six sets of Image files. The Introductory Files for 1994 and 1996 differed in that the March 1996 data contained an additional file. The 1994 data contained ten introductory files. 1) Description File (ASCII) 2) Errata File (ASCII) 3) Spectral Calibration File (ASCII and binary) 4) Radiometric Calibration File (ASCII and binary) 5) Geometric Correction (ASCII and binary) 6) Vignetting File (ASCII and binary) 7) On-board Calibration File (ASCII and binary) 8) Spike Threshold File (ASCII and binary) 9) Precal File (ASCII and binary) 10) Postcal File (ASCII and binary) The March 1996 data contained eleven introductory files. 1) Description File (ASCII) 2) Errata File (ASCII) 3) Spectral Calibration File (ASCII and binary) 4) Radiometric Calibration File (ASCII and binary) 5) Geometric Correction (ASCII and binary) 6) Vignetting File (ASCII and binary) 7) On-board Calibration File (ASCII and binary) 8) Spike Threshold File (ASCII and binary) 9) Precal File (ASCII and binary) 10) Postcal File (ASCII and binary) 11) On-Board Calibration Correction Coefficient File (ASCII and binary) (present for 1996 data tapes only) Following the introductory files on a tape, the 1994 and March 1996 AVIRIS data contain one or more sets of eight image related files. These files are: 1) Engineering File (ASCII and binary) 2) Navigation File (ASCII and binary) 3) Offset File (ASCII and binary) 4) Dark Current File (ASCII and binary) 5) Noise Spike Replace List (ASCII and binary) 6) Dropped Line List (ASCII and binary) 7) Auxiliary File (Contents Varies) 8) Image Data (ASCII and binary) New Format ---------- The new software puts entire runs on each tape, in tar format. The important info is the same, flight and run, but all scenes from a run are now included. When extracted, the following files should be found: PER FLIGHT LINE (i.e., occurs once per tar file/tape): *.avhdr general information about the flight line, *.brz browse image of the complete flight line, *.gain multiplication factors, radiance to 16-bit integer, *.geo geometric calibration data, *.log log information of the distribution processing, *.occ on-board calibration correction coefficients, *.post post flight line on-board calibrator data, *.pre pre flight line on-board calibrator data, *.rcc radiometric calibration coefficients, *.readme this file, *.spc spectral calibration file. PER SCENE (i.e., occurs once or several times per tar file/tape): *.drk1 first part of summed dark signal, *.drk2 second part of summed dark signal, *.eng engineering data, *.nav navigation data, *.img calibrated AVIRIS radiance (image) data, This listing, as well as more detailed information about the files, including formats, can be found in the *.readme file contained within each flight line. 9. Data Manipulations 9.1 Formulae 9.1.1 Derivation Techniques and Algorithms None given. 9.2 Data Processing Sequence 9.2.1 Processing Steps The JPL AVIRIS Data Facility (ADF) is responsible for low-level processing (up to level-1B), data archiving, and data distribution, along with assisting the hardware team in judging the performance of the AVIRIS instrument and modeling instrument anomalies. Upon receipt of an AVIRIS tape, the ADF first processes the first and last science runs (as opposed to preflight, runway, dewar check, or other runs) to determine whether or not the instrument performed properly over the course of the flight. If not, then AVIRIS is grounded until the anomaly or anomalies can be found and analyzed. This performance evaluation stage is mainly a subset of normal processing, but must be performed on the first and last science runs on a tape before normal processing can commence. The first step in processing a new tape is scanning the tape to make sure it matches the hardcopy list of runs provided by the AVIRIS Experiment Coordinator. Sometimes problems will result in short ‘throwaway’ or missing runs. These problems must be detected so that the proper site names can be matched with the good data. AVIRIS processing is done on a per run or per scene (512 lines) basis. However, as the AVIRIS archive media have limited storage space, no more than six scenes are processed at one time. Normal processing begins with downloading and decommutating the data, known as the download process. AVIRIS data is collected as 10-bit (12-bit for '95 and later) fields, but computers do not have any standard 10-bit data structures. Thus, the first processing reads the data from the tape, pads it with leading zeroes for storage in 16-bit integers, and writes it to disk. All data is stored in 16-bit integers, but some data (e.g., navigation) are actually encoded 32-bit floating point data. The ADF archiving process "expands" these fields to their proper size for easier understanding. In addition, the image data is reversed (within each scan line), since the data coming from the AVIRIS instrument, if displayed directly, is actually reversed from how the data would look from the aircraft. Each line of data is expanded and reversed, with any bad data marked as such, and then written to ADF archive media (currently 4mm tapes). The AVIRIS archiving process also compiles information about the image, navigation, and engineering data and stores it in the ADF database. This stored data is extracted at will with the Performance Evaluation Programs (PEPs) which also plot the data to model instrument behavior graphically. The AVIRIS quicklook images are also created during the archive process. These are initially stored as 2048x1536 SUN raster files, and show band 36 of each of the scenes in the run (up to the maximum of six scenes, longer runs will have more than one quicklook). These are printed and stored in folders in the ADF. Then they are processed to reduce them to 307x1536 strips with no header or separating data. These reduced quicklooks are then stored on the AVIRIS Anonymous FTP Site. When a request is made, the data must go through the Product Generation (PG) software. If the investigator wishes raw data, then PG only copies the data from archive tape to the desired distribution medium. However, most of the time the investigator wishes radiometrically corrected data. In addition to radiometric correction, the PG process performs detector readout delay correction when necessary. The data from the instrument's detectors are not read simultaneously. For each of the four spectrometers, the bands are read in order, so that the last band is read somewhat later than the first. As the instrument is scanning, the later bands are looking over a slightly different ground position than the first bands. Therefore, PG does a weighted average to "slide" the data back to it's proper position, insuring that for each pixel each of its 224 bands contains data from the same area on the ground. However, for the 1995 flight season the instrument hardware was improved so that there is no delay in 1995 data. The ADF also has software for general image processing which is used for image display and creation of pictures for the JPL Public Information Office and any technical conferences or presentations that ADF members are involved in. This software is also used by for detailed anomaly analysis. BORIS processing of the Level-1B AVIRIS image products includes: 1) Using developed software to extract and summarize information from each of the images on tape into ASCII files on disk, 2) Visual review of the ASCII summary and log files for anomalous items, 3) Interaction with the ADF staff regarding any anomalies, 4) Using developed software to inventory the images and descriptive information in the relational data base. 9.2.2 Processing Changes None given. 9.3 Calculations 9.3.1 Special Corrections/Adjustments None given. 9.3.2 Calculated Variables None given. 9.4 Graphs and Plots None given. 10. Errors 10.1 Sources of Error Uncertainty in AVIRIS calibration results from knowledge of the standards of calibration and stability of the AVIRIS sensor system. 10.2 Quality Assessment The spectral calibration is assessed to be within 5% in both spectral channel position and spectral response function FWHM. The radiometric calibration is assessed at better than 5%. The geometric calibration is assessed to be at the 7% of the reported along track and cross track spatial response function. The precision of the AVIRIS measurements is approximately 1 DN RMS. 10.2.1 Data Validation by Source In-flight calibration experiments are used to validate the calibration of AVIRIS. These are reported at the JPL Airborne Earth Science Workshops. 10.2.2 Confidence Level/Accuracy Judgement See section 10.2. 10.2.3 Measurement Error for Parameters None given. 10.2.4 Additional Quality Assessments None given. 10.2.5 Data Verification by Data Center Based on tape format information in the Description File of the AVIRIS tapes, and interactions with the ADF staff, BORIS developed software that calculates and extracts summary information from each AVIRIS tape. The summary information was reviewed visually and any anomalies were communicated to the ADF staff for assessment. 11. Notes 11.1 Limitations of the Data 11.2 Known Problems with the Data None given. 11.3 Usage Guidance None given. 11.4 Other Relevant Information None given. 12. Application of the Data Set Scientific investigations are ongoing using imaging spectrometry data in the disciplines of Ecology, Oceanography, Coastal and Inland Waters, Geology and Soils, Snow Hydrology, the Atmosphere, etc. 13. Future Modifications and Plans The signal-to-noise of AVIRIS and the absolute calibration are improved every year. In the six month period each year when AVIRIS is not collecting airborne data, the sensor is maintained and improved at JPL. Since its first flight in 1986, almost every subsystem of AVIRIS has been upgraded. Through these continuous improvements, AVIRIS has continued to incorporate new technology and remain a unique state-of-the-art imaging spectrometer. 14. Software 14.1 Software Description vtodxx: Transfers flight tape data to disk expxx: Expands data to 16 bit words peyy0: Evaluates performance of AVIRIS after flight tryy0: Performs trend analysis of AVIRIS data calyy0: Calibrates data to at sensor radiance distyy0: Distributes data xx: 10 or 12 bit data yy: 92,93,94,95,96,97,98... Software is Unix, C, Fortran The proprietary software packages used by the ADF are: IDL (Interactive Display Language) from Research Systems Inc. (RSI) ENVI (ENvironment for the Visualization of Images), also from RSI SQL Server and Open Client from Sybase BORIS personnel developed software and command procedures to: 1) Decode, check, and summarize the various level-1b AVIRIS data files, 2) Log the level-1b AVIRIS tapes into the BORIS database. The BORIS software is written in the C language and is operational on VAX 6410 and MicroVAX 3100 systems at NASA GSFC. The primary dependencies in the software are the tape I/O library and the Oracle data base utility routines. 14.2 Software Access Proprietary software used by the ADF can be obtained by the respective commercial companies which produce the software packages. The ADF plans to make AVIRIS software available upon request after it is formally coded and finalized. All of the described BORIS software is available upon request. See Section 15.4. 15. Data Access 15.1 Contact Information Ms. Beth Nelson BOREAS Data Manager NASA GSFC Greenbelt, MD (301) 286-4005 (301) 286-0239 (fax) beth@ltpmail.gsfc.nasa.gov 15.2 Data Center Identification See 15.1. 15.3 Procedures for Obtaining Data Users may place requests by telephone, electronic mail, or FAX. Data may also be obtained from the AVIRIS Data Facility. See the AVIRIS home page at http://makalu.jpl.nasa.gov/aviris.html. 15.4 Data Center Status/Plans The RSS-18 AVIRIS images are available from the EOSDIS ORNL DAAC (Earth Observing System Data and Information System) (Oak Ridge National Laboratory) (Distributed Active Archive Center). The BOREAS contact at ORNL is: ORNL DAAC User Services Oak Ridge National Laboratory Oak Ridge, TN (423) 241-3952 ornldaac@ornl.gov ornl@eos.nasa.gov 16. Output Products and Availability 16.1 Tape Products The BOREAS Level-1b AVIRIS data can be made available on 8 mm. 16.2 Film Products Color aerial photographs were taken from the ER-2 during AVIRIS data collection. BOREAS aircraft flight documentation, such as flight logs, video tapes, and photographs are available. 16.3 Other Products None. 17. References 17.1 Platform/Sensor/Instrument/Data Processing Documentation Please note that AVIRIS workshop proceedings are now on the web at the AVIRIS web site, http://makalu.jpl.nasa.gov/aviris.html. Green, R. O., Spectral Calibration Requirement for Earth-Looking Imaging Spectrometers in the Solar Reflected Spectrum, Applied Optics, in press Green, Robert O., Charles M. Sarture, Christopher J. Chovit, Jessica A. Faust, Pavul Hajek and H. Ian Novak, "AVIRIS: A New Approach to Earth Remote Sensing", Optics and Photonics News, Vol 6, No. 1, 1995 Green, Robert O., "Determination of the Inflight Spectral Calibration of AVIRIS Using Atmospheric Absorption Features", Proc. Fifth Annual Airborne Earth Science Workshop, JPL Public 95-1, 1995. Green, Robert O., "An Improved Spectral Calibration Requirement for AVIRIS", Proc. Fifth Annual Airborne Earth Science Workshop, JPL Public 95-1, 1995. Green, Robert O., James E. Conel, Mark Helmlinger, and Jeannette van den Bosch, "Inflight Radiometric Calibration of AVIRIS in 1994", Proc. Fifth Annual Airborne Earth Science Workshop, JPL Public 95-1, 1995. Sarture, C. M., T. G. Chrien, R. O. Green, M. L. Eastwood, J.J. Raney, and M. A. Herrnandez, "Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) sensor improvements for 1994 and 1995," Summaries of the Fifth Annual JPL Airborne Earth Sciences Workshop, JPL Publication 95-1, Vol. 1, Jet Propulsion Laboratory, Pasadena, California, pp. 145-148, 1995. Chrien, T. G., M. L. Eastwood, R. O. Green, C. M. Sarture, H. Johnson, C. Chovit, and P. Hajek, "Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) onboard calibration system," Summaries of the Fifth Annual JPL Airborne Earth Sciences Workshop, JPL Publication 95-1, Vol. 1, Jet Propulsion Laboratory, Pasadena, California, pp. 31-32, 1995. Green, Robert O., M. C. Helmlinger, J. E. Conel, J. M. van den Bosch, "Inflight Valication of the Calibration of the Airborne Visible/Infrared Imaging Spectrometer in 1993", Proc. Algorithm for Multispectral and Hyperspectral Imagery, SPIE, vol. 2231, 1994. Vane-G; Green-RO; Chrien-TG; Enmark-HT; Hansen-EG, et. al., The Airborne Visible Infrared Imaging Spectrometer (AVIRIS), Remote Sensing Of Environment, 1993, 44(2-3) 127-143 Green, Robert O., James E. Conel, Mark Helmlinger, Jeannette van den Bosch, Chris Chovit and Thomas Chrien, "Inflight Calibration of AVIRIS in 1992 and 1993",Proc. Fourth Annual Airborne GeoScience Workshop, JPL Public 93-26, 1993. Green, Robert O., "Use of Data from the AVIRIS Onboard Calibrator"Proc. Fourth Annual Airborne GeoScience Workshop, JPL Public 93-26, 1993. Robert O. Green, Thomas G. Chrien, Pia J. Nielsen, Charles M. Sarture, Bjorn T. Eng, Christopher Chovit, Alex T. Murray, Michael L. Eastwood and H. Ian Novack, "Airborne Visible/Infrared Imaging Spectrometer (AVIRIS): Recent Improvements to the Sensor and Data Facility", SPIE Conf. 1937, Imaging Spectromety of the Terrestrial Environment, in press, 12 p. 1993. Chrien, T. G., and R. O. Green, "Instantaneous field of view and spatial sampling of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)," Summaries of the Fourth Annual JPL Airborne Earth Sciences Workshop, JPL Publication 93-26, Vol. 1, Jet Propulsion Laboratory, Pasadena, California, pp. 23-26, 1993. Green, Robert O., James E. Conel and Thomas G. Chrien, "Airborne Visible- Infrared Imaging Spectrometer (AVIRIS): Sensor System, Inflight Calibration and Reflectance Calculation", International Symposium on Spectral Sensing Research, pp. 22, in press, 1992. Green, Robert O., Steve Larson and Ian Novack, "Calibration of AVIRIS digitized data", Proc. Third Annual Airborne Geoscience Workshop, JPL Publication 92-14, pp. 1992. Green, R. O. et al., "In-flight Calibration of the Spectral and Radiometric Characteristics of AVIRIS in 1991", Proc. Third Annual Airborne Geoscience Workshop, JPL Publication 92-14, 199 Green,R.O., James E. Conel, Jack Margolis, Carol Bruegge and Gordon Hoover, "An Inversion Algorithm for Retrieval of Atmospheric and Leaf Water Absorption from AVIRIS Radiance with Compensation for Atmospheric Scattering", in Proceedings of the Third AVIRIS Workshop, R.O. Green , editor, JPL Publication, 1991. Green, R.O., Steve Larson and Ian Novack, (1991), Calibration of AVIRIS digitized data,in Proceedings of the Third AVIRIS Workshop, R.O. Green , editor, JPL Publication, 1991. Green, R. O. and G. Vane, "Validation/calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) in-flight", Proc. SPIE Conference on Aerospace Sensing, Imaging Spectroscopy of the Terrestrial Environment, Orlando, Florida, 16-20 April, 1990. Chrien, T.G., R.O. Green, and M.L. Eastwood, "Accuracy of the Spectral and Radiometric Laboratory Calibration of the Airborne Visible/Infrared Imaging Spectrometer", in Proceedings of the Second Airborne Visible/INfrared Imaging Spectrometer (AVIRIS) Workshop, JPL Pub. 90-54, 1-14.1990 Chrien, T. G., R. O. Green, and M. L. Eastwood, "Accuracy of the Spectral and Radiometric Laboratory Calibration of the Airborne Visible/Infrared Imaging Spectrometer", Proc. SPIE Conference on Aerospace Sensing, Imaging Spectroscopy of the Terrestrial Environment, Orlando, Florida, 16-20 April, 1990. Green, R.O., J.E. Conel, V. Carrere, C.J. Bruegge, J.S. Margolis, M.Rast, and G. Hoover, "Determination of the in-flight spectral and radiometric characteristics of the airborne visible/infrared imaging spectrometer (AVIRIS), in Proceedings of the Second Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Workshop, JPL Pub. 90-54, 15-34. 1990. Green, R.O., J.E. Conel, V. Carrere, C.J. Bruegge, J.S. Margolis, M.Rast, and G. Hoover, "Inflight validation and Calibration of the Spectral and Radiometric Characteristics of the airborne visible/infrared imaging spectrometer (AVIRIS)", Proc. SPIE Conference on Aerospace Sensing, Imaging Spectroscopy of the Terrestrial Environment, Orlando, Florida, 16-20 April, 1990. Chrien, T. G., R. O. Green, M. L. Eastwood, "Accuracy of the spectral and radiometric laboratory calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)," SPIE Vol. 1298, Imaging Spectroscopy of the Trestle Environment, pp. 37-49, 1990. Green, R.O. (1989). Calibration of the Airborne Visible/Infrared imaging spectrometer (AVIRIS), Imaging Spectroscopy: Fundamentals and prospective applications, JRC, ISPRA, Italy, 23-27 October 1989, in press. Green, R.O. and G. Vane (1988). In-flight determination of AVIRIS spectral, radiometric, spatial and signal-to-noise characteristics using atmospheric and surface measurements from the vicinity of the rare-earth-bearing carbonatite at Mountain Pass, California, in Proceedings of the AVIRIS Performance Evaluation Workshop, Gregg Vane, editor, JPL Publication, in press. Vane, G., T.G. Chrien, J.H. Reimer, R.O. Green, and J.E. Conel (1988). Comparison of laboratory calibrations of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) at the beginning and end of the first flight season, Proc. SPIE Conference on Recent Advances in Sensors, Radiometry and Data Processing for Remote Sensing, Orlando, Florida, 4-8 April, 1988, 924, in press. Conel, J.E., R.O. Green, R.E. Alley, C.J. Bruegge, V. Carrere, J.S. Margolis, G. Vane, T.G. Chrien, P.N. Slater, S.F. Biggar, P.M. Teillet, R.D. Jackson and M.S. Moran (1988). In-flight radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), Proc. SPIE Conference on Recent Advances in Sensors, Radiometry and Data Processing for Remote Sensing, Orlando, Florida, 4- 8 April, 1988, 924. Conel, J.E., G. Vane, R.O. Green, R.E. Alley, V. Carrere, A. Gabell and C.J. Bruegge (1988). Airborne Visible/Infrared Imaging Spectrometer (AVIRIS): In- flight radiometric calibration and the determination of surface reflectance, Proc. 4th Int'l Coll. on Spectral Signatures of Objects in Remote Sensing, Aussois, France, 18-22 January 1988, ESA SP-287, 293-296. 17.2 Journal Articles and Study Reports Green, R. O., Dozier, J., Inversion for the Vapor, Liquid and Frozen Phases of the Water Molecule over Mount Rainier, WA from Solar Reflected Spectra Measured by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), American Geophysical Union, San Francisco, Spring 1996. Green, R. O., Estimation of Biomass Fire Temperature and Areal Extent from Calibrated AVIRIS Spectra, Proc. Sixth Annual Airborne Earth Science Workshop, Jet Propulsion Laboratory, JPL Public 96-, Vol. 1, March 3-5, 1996. Green, R. O., Dar A. Roberts and James E. Conel, Characterization and Compensation of the Atmosphere for the Inversion of AVIRIS Calibrated Radiance to Apparent Surface Reflectance, Proc. Sixth Annual Airborne Earth Science Workshop, Jet Propulsion Laboratory, JPL Public 96-, Vol. 1, March 3-5, 1996. (submitted to peer-review Journal) Green, R. O. and Jeff Dozier, Retrieval of Surface Snow Grainsize and Melt Water from AVIRIS Spectra, Proc. Sixth Annual Airborne Earth Science Workshop, Jet Propulsion Laboratory, JPL Public 96-, Vol. 1, March 3-5, 1996. Green R. O., Dar A. Roberts, John A. Gamon and Jeff Dozier, "Expression of the Molecules Chlorophyll and Liquid Water in the Vegetation Canopies of the Old Jack Pine Site at BOREAS as Derived from Spectra Measured by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)", American Geophysical Union, Spring-95, BOREAS-Session, Baltimore, 1995 Green, R.O., and Dar A. Roberts, "Comparison of MODTRAN Modeled and AVIRIS Measured Water Vapor Absorption in the Solar Reflected Spectrum Over a Range from 0.5 to 15.0 Precipitable Millimeters on the Slopes of the 5700 meter Mexican Volcano, Pico de Orizaba.",18th Annual Review Conference on Atmospheric Transmission Models, Phillips Lab, Hanscom AFB, 6-8 June 1995 Green, R. O., Dar A. Roberts, James E. Conel, and Jeff Dozier, "Imaging Spectrometer Measurement of Water Vapor in the 400 to 2500 nm Spectral Region", Optical Society of America, Optical Remote Sensing of the Atmosphere, Salt Lake City, Feb 5-9, Vol 2, 1995 Green, Robert O., James E. Conel, and Dar A. Roberts, "Measurement of Atmospheric Water Vapor, Leaf Liquid Water and Reflectance With AVIRIS at the Boreal Ecosystem-Atmosphere Study: Initial Results", Proc. Fifth Annual Airborne Earth Science Workshop, JPL Public 95-1, 1995. Green, Robert O. and Jeff Dozier, "Measurement of the Spectral Absorption of Liquid Water in Melting Snow With an Imaging Spectrometer", Proc. Fifth Annual Airborne Earth Science Workshop, JPL Public 95-1, 1995. Green, Robert O. and Dar A. Roberts, "Vegetation Species Composition and Canopy Architecture Information Expressed in Leaf Water Absorption Measured in the 1000 nm and 2200 nm Spectral Region by an Imaging Spectrometer", Proc. Fifth Annual Airborne Earth Science Workshop, JPL Public 95-1, 1995. Green, Robert O., James E. Conel, and Dar A. Roberts,"Estimation of Aerosol Optical Depth and Additional Atmospheric Parameters for the Calculation of Apparent Reflectance from Radiance Measured by the Airborne Visible/Infrared Imaging Spectrometer", Proc. Fourth Annual Airborne GeoScience Workshop, JPL Public 93-26, 1993. Green, Robert O., and James E. Conel, "Atmospheric Correction of Data collected by Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) and Application to the Advanced Land Remote Sensing Systems", Workshop on Atmospheric Correction of Landsat Imagery, 29 June to 1 July, Torrance, CA, 6 p.1993 Sellers, P., F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). Sellers, P., F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). Sellers, P., F. Hall, K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). Sellers, P., F. Hall, K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J. Ranson, D. Lettenmaier, and D.E. Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and early results from the 1994 field year. Bulletin of the American Meteorological Society. 76(9):1549-1577. Sellers, P., F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue. 17.3 Archive/DBMS Usage Documentation None. 18. Glossary of Terms Hyperspectral - Refers to image data that contains several image bands, usually 30 to hundreds. 19. List of Acronyms ADF - AVIRIS Data Facility ARC - Ames Research Center ASCII - American Standard Code for Information Interchange ASAS - Advanced Solid-state Array Spectrometer AVIRIS - Airborne Visible/InfraRed Imaging Spectrometer BOREAS - BOReal Ecosystem-Atmosphere Study BORIS - BOREAS Information System BSQ - Band Sequential CD-ROM - Compact Disk-Read-Only Memory DAAC - Distributed Active Archive Center DAT - Digital Archive Tape EOS - Earth Observing System EOSDIS - EOS Data and Information System GSFC - Goddard Space Flight Center HDF - Hierarchical Data Format IFOV - Instantaneous Field-of-View JPL - Jet Propulsion Laboratory MAS - MODIS Airborne Simulator MODIS - MODerate Imaging Spectroradiometer MODLAND - MODIS Land Group NAD83 - North American Datum 1983 NASA - National Aeronautics and Space Administration NIST - National Institute of Standards and Technology ORNL - Oak Ridge National Laboratory PEP - Performance Evaluation Program PG - Product Generator URL - Uniform Resource Locator 20. Document Information 20.1 Document Revision Date Written: 14-May-1997 Last Updated: 06-Jul-1998 20.2 Document Review Date(s) BORIS Review: 12-Feb-1997 Science Review: 29-Jun-1998 20.3 Document 20.4 Citation 20.5 Document Curator 20.6 Document URL hyperspectral spectrometry airborne sensors reflectance spectral signature boreal forest remote sensing RSS18_AVIRIS_L1B.doc 07/07/98